The aptitude to render graphics on prime of different working functions on the Android working system permits distinctive person interface enhancements and functionalities. For instance, a person would possibly make use of this performance to create a floating widget displaying system info whereas concurrently utilizing an online browser or different utility. That is completed by means of system-level permissions and cautious administration of the window layer.
This characteristic gives builders with the power to supply overlays for numerous functions, from bettering accessibility to rising productiveness. Traditionally, the power to show visible components on prime of different functions was reserved for system-level processes. Nonetheless, trendy Android variations grant particular permissions that permit third-party functions to leverage this performance, offered customers explicitly grant the required permission. This contributes to a extra customizable and interactive person expertise, significantly in multitasking situations.
The next sections will delve into the technical points concerned in implementing this functionality, together with the mandatory permissions, implementation approaches, and issues for person expertise and safety.
1. System Alert Window
The “System Alert Window” permission represents a basic element of the Android working system’s overlay performance, performing because the linchpin for functions looking for the potential to render visible components on prime of different working processes. With out this permission, functions can not execute the core operate of graphical overlay, rendering it inconceivable to realize the specified ‘drawing over different apps’ habits.
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Permission Granting and Revocation
Person consent is paramount. The Android system mandates express person approval earlier than an utility can purchase the “System Alert Window” permission. This includes navigating to system settings and granting the permission. Customers retain the suitable to revoke this permission at any time, successfully disabling the applying’s means to attract overlays. This mechanism gives a vital layer of management and safety, stopping unauthorized visible interference.
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Window Sort Specification
The “System Alert Window” permission permits the creation of home windows with a particular kind that determines their placement inside the window layering hierarchy. These window varieties dictate whether or not the overlay will seem above standing bars, enter strategies, or different functions. Choosing the suitable window kind is important to make sure the overlay capabilities as supposed with out obstructing important system components. Incorrect window kind choice could result in undesired visible conflicts or stop the overlay from being seen in any respect.
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Z-Order and Visibility
The relative stacking order (Z-order) of those home windows is managed by the system, with newer overlays sometimes showing on prime. Nonetheless, functions can programmatically affect their Z-order to some extent. Environment friendly administration of Z-order is essential for stopping unintentional obscuration of different utility components and guaranteeing the overlay stays seen and conscious of person interplay. Poor Z-order administration can result in a degraded person expertise, significantly when a number of functions try to attract overlays concurrently.
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Safety Implications
The ability to attract over different functions introduces potential safety vulnerabilities. Malicious functions might exploit this permission to create faux system dialogs, seize delicate person enter, or conduct phishing assaults. Due to this fact, Android imposes strict limitations and pointers on using “System Alert Window”. Builders are liable for guaranteeing their overlays are clear, clearly identifiable, and don’t mimic system UI components. Failure to stick to those pointers may end up in utility rejection or removing from the Google Play Retailer.
In abstract, the “System Alert Window” permission acts as a important gateway, regulating entry to the performance permitting functions to attract visible components over different working processes. The permission’s granting, window kind specification, Z-order administration, and inherent safety implications underscore the complexity and potential threat related to this performance, highlighting the necessity for accountable implementation and stringent person management.
2. Overlay Permission
The “Overlay Permission” serves because the foundational requirement for any Android utility aiming to implement the performance of displaying visible components on prime of different concurrently working functions. Its existence represents a binary situation; with out this permission, an utility is essentially incapable of “drawing over different apps android.” The connection is causal: the granting of the permission is a needed antecedent for the performance to grow to be operational. Contemplate, for instance, a floating calculator utility. Its means to seem superimposed on different functions, equivalent to an online browser or a doc editor, hinges solely on the person having explicitly granted the requisite overlay permission. The shortage of this permission would render the calculator confined to standard utility habits, unable to manifest as a persistent overlay.
Moreover, the sensible significance of understanding this relationship extends to improvement workflows and person expertise issues. Builders should meticulously deal with situations the place the person has not granted the overlay permission, implementing sleek degradation or clear prompts guiding the person towards granting the mandatory entry. A standard apply includes displaying an informative dialog explaining the aim of the permission and offering a direct hyperlink to the system settings the place the permission may be enabled. This strategy promotes transparency and enhances person belief. One other use-case is in customized system launchers, which make the most of the overlay permission to show fast entry menus and widgets on prime of the person’s at present energetic utility. Once more, the right dealing with of conditions the place the overlay permission has not been granted is important for a constructive person expertise.
In conclusion, the overlay permission is an indispensable element of implementing the potential to render graphics above different working functions on the Android platform. Its presence determines the feasibility of the performance, and its correct dealing with instantly impacts each the person expertise and the safety issues surrounding functions that make the most of this highly effective characteristic. Builders should acknowledge the criticality of this permission and implement strong mechanisms to handle situations the place it’s both granted or denied, fostering a safe and user-friendly atmosphere.
3. WindowManager Management
WindowManager Management is a pivotal side of implementing the potential to render visible components on prime of different functions inside the Android atmosphere. This management mechanism gives the interface by means of which an utility manipulates the window layering system, figuring out the visibility, place, and habits of overlay components. The “drawing over different apps” performance depends closely on the power so as to add, replace, and take away home windows from the WindowManager, successfully orchestrating the looks and interactivity of the overlay. An instance of that is seen in display recording functions, the place the overlay displaying recording controls is managed through WindowManager, permitting it to stay seen whatever the utility at present in focus.
The WindowManager.LayoutParams class performs a vital function in defining the traits of an overlay window. Parameters equivalent to window kind (e.g., TYPE_APPLICATION_OVERLAY, TYPE_SYSTEM_ALERT), flags (e.g., FLAG_NOT_FOCUSABLE, FLAG_NOT_TOUCH_MODAL), and pixel format are configured by means of this class. As an example, setting the FLAG_NOT_FOCUSABLE permits the overlay to obtain contact occasions with out stealing focus from the underlying utility. Equally, the window kind dictates the layer by which the overlay is positioned, impacting its visibility relative to different system components. The right configuration of those parameters is important to realize the specified visible impact and interplay mannequin of the overlay. A sensible utility of this may be present in accessibility instruments, the place overlays present real-time textual content translation or display magnification. Such overlays should be rigorously managed by means of WindowManager to make sure they’re each seen and non-intrusive.
In conclusion, WindowManager Management constitutes an indispensable element within the implementation of “drawing over different apps”. It gives the means to create, configure, and handle overlay home windows, dictating their look, habits, and interplay with the underlying system. Whereas highly effective, efficient utilization of WindowManager requires a deep understanding of its parameters and their implications, in addition to adherence to finest practices to make sure stability, safety, and a constructive person expertise. Challenges exist in coordinating a number of overlays and stopping conflicts with system UI components, highlighting the necessity for cautious planning and testing throughout improvement.
4. Canvas Manipulation
Canvas Manipulation types a important technical layer within the implementation of visible overlays on the Android platform. This system facilitates direct pixel-level management, enabling builders to render customized graphics, animations, and textual content components on prime of different functions. The performance to “draw over different apps android” hinges on the power to control the canvas object, which serves because the drawing floor for the overlay window.
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Drawing Customized UI Parts
Canvas manipulation gives the power to create bespoke person interface components that aren’t available by means of commonplace Android UI parts. As an example, a system monitoring device would possibly render a real-time graph of CPU utilization as an overlay. This requires drawing strains, shapes, and textual content dynamically onto the canvas, responding to modifications in system information. This stage of customization could be unattainable with out direct canvas manipulation. Equally, drawing signatures or annotations on screenshots displayed as overlays necessitates exact management over pixel placement on the canvas.
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Implementing Animations and Transitions
Animations and transitions considerably improve the person expertise of overlays. Canvas manipulation permits for the creation of complicated animations by iteratively redrawing the canvas with barely modified parameters. A loading indicator overlay, for instance, could use canvas rotation and coloration changes to create a visually interesting animation. Furthermore, transitions between totally different overlay states (e.g., increasing a minimized widget) may be applied by regularly modifying the canvas content material over time, offering a easy and interesting visible expertise.
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Dynamic Textual content Rendering
The power to render textual content dynamically on the canvas is important for displaying info and offering directions inside an overlay. Canvas manipulation permits builders to regulate the font, dimension, coloration, and placement of textual content with pixel-level accuracy. That is significantly helpful for displaying real-time information, equivalent to inventory costs or sports activities scores, on prime of different functions. Moreover, dynamic textual content rendering can be utilized to supply contextual assist or steering to customers inside the overlay, adapting the displayed textual content based mostly on the present state of the applying.
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Picture Compositing and Filtering
Canvas manipulation permits the compositing of a number of pictures and the applying of varied filters to create complicated visible results. An utility would possibly overlay a semi-transparent watermark onto the display to discourage unauthorized display recording. This includes loading the watermark picture, setting its transparency, and drawing it onto the canvas in a particular location. Moreover, canvas manipulation can be utilized to use picture filters, equivalent to blurring or coloration changes, to reinforce the visible enchantment of the overlay or to create particular results, like highlighting sure areas of the display.
These points of Canvas Manipulation are indispensable for functions looking for to successfully draw over different apps on Android. From creating customized UI components and implementing animations to rendering dynamic textual content and compositing pictures, canvas manipulation gives the flexibleness and management essential to ship compelling and informative overlay experiences. The accountable and environment friendly use of those strategies is essential for guaranteeing a constructive person expertise and minimizing efficiency affect on underlying functions.
5. Contact Occasion Dealing with
The power to intercept and course of person contact enter is intrinsically linked to the performance of “drawing over different apps android.” With out strong contact occasion dealing with, an overlay would exist merely as a passive visible aspect, missing interactivity and considerably diminishing its utility. The overlay, in essence, turns into non-functional if it can not reply to person enter. The cause-and-effect relationship is direct: person contact occasions set off the execution of predefined actions inside the overlay utility, enabling the overlay to operate as an interactive interface. For instance, a floating video participant, rendering on prime of different functions, requires contact occasion dealing with to handle playback controls (play, pause, quantity adjustment) instantly on the overlay window. The absence of this functionality would necessitate switching again to the video participant’s foremost utility window for management, defeating the aim of the overlay.
Efficient contact occasion dealing with in overlays calls for cautious consideration of occasion propagation and coordination with the underlying utility. Relying on the supposed habits, the overlay could both eat the contact occasion, stopping it from reaching the applying beneath, or go the occasion by means of. This selection has substantial implications for the person expertise. As an example, a drawing utility applied as an overlay should eat contact occasions to permit the person to attract instantly on the display. Conversely, a notification show overlay would possibly permit contact occasions to go by means of to the underlying utility until the person interacts with the notification itself. Libraries like “GestureDetector” and cautious implementation of “onTouchEvent” are generally employed to handle numerous contact gestures (single faucet, double faucet, swipe) and their corresponding actions. The sensible significance of understanding the refined interaction between occasion dealing with, visible presentation, and utility coordination is paramount in delivering a seamless and intuitive person expertise.
In abstract, contact occasion dealing with types an indispensable element of any utility looking for to implement the “drawing over different apps” functionality. It governs the interactivity of the overlay, dictates its responsiveness to person enter, and determines its total usability. Challenges usually come up in managing contact occasion conflicts between the overlay and the underlying utility, requiring cautious design and implementation to make sure each functions operate harmoniously. The power to deal with contact occasions successfully shouldn’t be merely a technical requirement however somewhat a basic determinant of the overlay’s worth and its means to combine seamlessly with the Android ecosystem.
6. Z-Order Administration
Z-Order Administration performs a important function within the implementation of functions designed to render graphics on prime of different working functions on the Android platform. It governs the visible hierarchy of overlapping home windows, figuring out which components seem within the foreground and that are obscured. The performance of “drawing over different apps android” is instantly depending on efficient Z-Order Administration to make sure overlays are seen and interactable as supposed.
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Window Layering Hierarchy
The Android system employs a layered windowing system the place every window is assigned a Z-order, dictating its place relative to different home windows. Overlays, applied to “draw over different apps android,” should be positioned inside an applicable layer to make sure visibility above the goal utility. Window varieties, equivalent to `TYPE_APPLICATION_OVERLAY` and `TYPE_SYSTEM_ALERT`, affect this placement. For instance, a floating widget displaying system info must reside in the next layer than the applying it overlays to stay seen. Incorrect layering may end up in the overlay being obscured, rendering it non-functional.
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Managing Overlapping Overlays
In situations the place a number of functions try to “draw over different apps android” concurrently, Z-Order Administration turns into significantly complicated. The system should resolve conflicts to find out the stacking order of those overlays. Functions can affect their Z-order to some extent, however the system retains final management. This will result in surprising habits if a number of overlays compete for a similar display house. As an example, two floating functions displaying notifications would possibly obscure one another until their Z-order is rigorously managed, doubtlessly requiring dynamic adjustment based mostly on person interplay or precedence.
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Influence on Person Interplay
The Z-order instantly impacts how customers work together with overlays and underlying functions. An overlay designed to seize contact occasions should be positioned accurately within the Z-order to obtain these occasions. If the overlay is positioned behind one other window, it won’t obtain contact enter, rendering it unusable. Equally, if an overlay unintentionally obscures important components of the underlying utility, it could possibly hinder usability. Contemplate a display recording utility; the overlay displaying recording controls should be positioned in a fashion that doesn’t hinder important components of the applying being recorded.
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System Window Administration Issues
System-level home windows, such because the standing bar and navigation bar, additionally take part within the Z-order hierarchy. Functions that “draw over different apps android” should think about these system components to make sure their overlays don’t battle with them. Overlays that inappropriately obscure system UI components can result in a degraded person expertise and potential system instability. For instance, an overlay that utterly covers the standing bar would possibly stop customers from accessing system notifications, requiring cautious consideration of window flags and Z-order placement to keep away from such conflicts.
In abstract, efficient Z-Order Administration is essential for functions that “draw over different apps android”. The layering of home windows, the dealing with of overlapping overlays, and the affect on person interplay are all instantly ruled by how the Z-order is managed. Poor Z-Order Administration can result in usability points, system instability, and a unfavourable person expertise, highlighting the significance of cautious planning and implementation.
7. Useful resource Optimization
Functions able to rendering graphics atop different functions within the Android atmosphere are inherently topic to stringent efficiency calls for. The exercise of “drawing over different apps android” introduces an extra computational load, doubtlessly impacting the responsiveness and battery lifetime of the gadget. Useful resource optimization, due to this fact, turns into an indispensable element. The introduction of an overlay, if poorly optimized, can demonstrably degrade the efficiency of the underlying utility. A poorly optimized floating video participant, as an illustration, might eat extreme CPU cycles, resulting in dropped frames and stuttering playback, even inside the underlying utility.
Sensible useful resource optimization methods embody numerous strategies. Limiting the frequency of redraws is paramount; overlays ought to solely be up to date when needed, somewhat than repeatedly refreshing the canvas. Using environment friendly drawing strategies, equivalent to using {hardware} acceleration the place potential and minimizing using alpha mixing, can considerably scale back the processing overhead. Moreover, cautious administration of bitmap sources, avoiding pointless allocations and aggressively recycling bitmaps when they’re not wanted, contributes to diminished reminiscence consumption. For instance, an accessibility device that gives real-time display magnification as an overlay should implement these optimization methods to keep away from sluggish efficiency and guarantee a easy person expertise.
In conclusion, the seamless integration of overlays into the Android ecosystem necessitates a robust emphasis on useful resource optimization. The efficiency affect of “drawing over different apps android” may be important, however by means of cautious coding practices and the applying of optimization strategies, builders can mitigate these results and ship overlays which might be each visually interesting and performant. This requires a proactive strategy, incorporating useful resource optimization issues all through the event lifecycle to make sure a constructive and environment friendly person expertise. The purpose is to attenuate the efficiency affect on the gadget, permitting it to supply a high-quality person expertise with out pointless efficiency drains or battery consumption points.
8. Safety Issues
The power for an utility to render visible components over different working functions presents inherent safety dangers inside the Android working system. This functionality, whereas enabling respectable functionalities, additionally opens avenues for malicious actors to take advantage of person belief and doubtlessly compromise system integrity.
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Overlay Assaults
Overlay assaults symbolize a major menace. Malicious functions can create faux system dialogs that mimic respectable prompts, tricking customers into granting delicate permissions or divulging confidential info. As an example, a faux “System Replace” dialog displayed over a banking utility might request the person’s credentials. The unsuspecting person, believing the immediate originates from the system, could inadvertently expose their banking particulars. The “drawing over different apps android” characteristic, when abused on this method, permits the malicious overlay to convincingly masquerade as a trusted system element, resulting in potential information breaches.
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Clickjacking
Clickjacking includes concealing malicious actions beneath seemingly innocuous UI components. A clear overlay positioned over respectable buttons or hyperlinks can redirect person enter to unintended locations. A person meaning to click on a “Like” button on a social media utility would possibly unknowingly set off a fee authorization on the overlay. The power to “draw over different apps android” is exploited to create this misleading layer, manipulating person interplay with out their consciousness. This kind of assault may end up in unauthorized expenses, information theft, or the set up of malware.
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Knowledge Exfiltration
Malicious overlays can seize delicate info displayed on the display, equivalent to passwords, bank card numbers, or private messages. By repeatedly monitoring the display content material and transmitting the captured information to a distant server, attackers can exfiltrate confidential info with out person consent. The “drawing over different apps android” functionality gives the mechanism for the overlay to stay persistently energetic and monitor display content material, turning it right into a silent surveillance device. This kind of assault is especially harmful because it operates within the background, usually undetected by the person till important injury has been achieved.
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Permission Abuse
Even seemingly benign functions with the “draw over different apps android” permission can pose a threat. Over time, builders would possibly introduce malicious code into beforehand trusted functions by means of updates. Alternatively, vulnerabilities within the utility’s code may be exploited by attackers to inject malicious overlays. In these situations, the initially granted permission turns into a gateway for unauthorized entry and malicious exercise. The beforehand respectable utility transforms right into a Malicious program, utilizing its privileged place to carry out actions past its unique scope.
These safety issues spotlight the inherent dangers related to granting the power to “draw over different apps android.” Whereas respectable functions make the most of this functionality for useful functions, the potential for abuse necessitates vigilance and the implementation of strong safety measures to guard customers from malicious overlays and their related threats.
Steadily Requested Questions Concerning “Drawing Over Different Apps Android”
The next addresses widespread inquiries and misconceptions surrounding the performance of drawing visible components over different working functions on the Android working system. It’s supposed to supply clear and concise info for builders and customers alike.
Query 1: What constitutes “drawing over different apps android”?
This refers back to the functionality of an Android utility to render visible components, equivalent to home windows, graphics, or textual content, on prime of different concurrently working functions. That is achieved by means of using particular system permissions and the Android WindowManager API.
Query 2: What permissions are required to implement “drawing over different apps android”?
The first permission required is “SYSTEM_ALERT_WINDOW”. This permission should be explicitly granted by the person through system settings earlier than an utility can draw overlays. With out this permission, the performance won’t function.
Query 3: What are the potential safety dangers related to “drawing over different apps android”?
This performance may be exploited for malicious functions, together with overlay assaults, clickjacking, and information exfiltration. Attackers can create faux system dialogs to trick customers into granting permissions or divulging delicate info. Customers ought to train warning when granting this permission.
Query 4: How does an utility handle contact occasions when “drawing over different apps android”?
Functions should implement contact occasion dealing with mechanisms to reply to person enter on the overlay window. The applying can both eat the contact occasion or go it by means of to the underlying utility, relying on the specified habits.
Query 5: How can efficiency be optimized when “drawing over different apps android”?
Useful resource optimization is important to attenuate the affect on system efficiency. This contains limiting redraw frequency, using {hardware} acceleration, and effectively managing bitmap sources. Poorly optimized overlays can considerably degrade gadget responsiveness and battery life.
Query 6: How does the Android system handle Z-order when a number of functions are “drawing over different apps android”?
The Android system employs a layered windowing system the place every window is assigned a Z-order, figuring out its visible precedence. System components, such because the standing bar, additionally take part within the Z-order hierarchy. Overlays should be appropriately layered to make sure visibility and keep away from conflicts.
In abstract, the power for an utility to render components over different apps presents each highly effective capabilities and inherent safety dangers. Customers should train warning when granting the SYSTEM_ALERT_WINDOW permission and builders should guarantee accountable and performant implementation.
The next part will discover finest practices and pointers for implementing “drawing over different apps android” in a safe and user-friendly method.
Ideas for Implementing “Drawing Over Different Apps Android” Responsibly
The next pointers present important suggestions for builders looking for to implement the “drawing over different apps android” performance whereas prioritizing person expertise, safety, and system stability.
Tip 1: Request the SYSTEM_ALERT_WINDOW Permission Judiciously: Implement a transparent and concise rationalization to the person detailing the exact explanation why the overlay permission is important for the applying’s performance. Keep away from imprecise or deceptive justifications. A screen-dimming utility, for instance, ought to explicitly state that the permission permits it to cut back display brightness past the system’s default settings.
Tip 2: Decrease the Overlay Footprint: Design overlays to be as unobtrusive as potential. Keep away from protecting important UI components of the underlying utility. A floating notification widget, as an illustration, ought to be designed to be small, clear, and simply dismissible to attenuate disruption to the person’s workflow.
Tip 3: Implement Strong Contact Occasion Dealing with: Make sure that contact occasions are accurately dealt with inside the overlay window. Keep away from by accident intercepting contact occasions supposed for the underlying utility. If the overlay shouldn’t be supposed to be interactive, explicitly go contact occasions by means of to the underlying utility to take care of performance.
Tip 4: Prioritize Useful resource Optimization: Decrease the computational overhead related to rendering the overlay. Make use of environment friendly drawing strategies, restrict redraw frequency, and handle reminiscence sources rigorously. Repeatedly monitor the applying’s efficiency to determine and handle potential bottlenecks which will affect system responsiveness.
Tip 5: Adhere to Materials Design Rules: Keep visible consistency with the Android system by adhering to Materials Design rules. Keep away from mimicking system UI components, equivalent to dialog bins or notifications, to stop person confusion and potential exploitation.
Tip 6: Frequently Monitor for Safety Vulnerabilities: Proactively handle potential safety vulnerabilities within the utility code. Keep knowledgeable about widespread overlay assault vectors and implement applicable safeguards to stop malicious exploitation. Frequently replace dependencies and libraries to patch recognized safety flaws.
Tip 7: Present an Simple Option to Disable the Overlay: Supply customers a simple mechanism to disable the overlay performance utterly. This gives customers with management over the applying’s habits and permits them to simply disable the overlay whether it is inflicting issues or conflicts.
The following pointers emphasize the significance of accountable implementation when working with the “drawing over different apps android” characteristic. By adhering to those pointers, builders can decrease dangers and ship a constructive person expertise.
The ultimate part summarizes key takeaways and gives a concluding perspective on using this performance.
Conclusion
The previous sections have explored the technical and safety implications of “drawing over different apps android.” This performance, whereas providing distinctive capabilities for utility enhancement and customization, presents important challenges associated to person expertise, system stability, and potential malicious exploitation. Implementing such options requires a complete understanding of the underlying Android windowing system, related permissions, and proactive mitigation of safety dangers.
The accountable utility of the “drawing over different apps android” characteristic necessitates a dedication to transparency, person management, and strong safety practices. Builders should rigorously weigh the advantages in opposition to the potential dangers and prioritize the person’s finest pursuits. Continued vigilance and adherence to evolving safety pointers are essential to sustaining the integrity of the Android ecosystem and fostering person belief in functions that make the most of this highly effective, but doubtlessly harmful, functionality.
